Lab Manual Flashcards
Describe that light travels in a straight line
a form of energy that travels from one place to the other as an electro-magnetic wave, its travels in a straight line called a ray
Name the titles of parts of a light wave
crest - top of the wave
troph - lowest point of wave
wavelength - the distance from one crest to the next
amplitude - the height of each wave
frequency - how many waves are produced per second
From smallest to largest list the suns spectrum of different wavelengths
gamma rays x rays ultra violet visible light Infrared Microwaves Radio Waves
What is the electromagnetic Spectrum
The range of wavelengths or frequencies over which electromagnetic radiation extends
What is visible/white light
visisble light is a section of the electromagnetic spectrum made up of white light which is made up of all the colours we can see. For example when someone looks a a green pen, light that is on it is all different colours but only reflects the green colour back to the eyes
What is the different between diffuse and regular reflection
regular - when light reflects off a smooth surface it produces a clear image as all light rays are reflected in the same direction
diffuse - when light hits a rough surface it reflects or scatters light in many directions and no image is formed
What is the law of reflection
That the angle of incidence is equal to the angle of reflection
Recall types of images made by plane mirrors, concave or convex
plane mirrorrs - virtual, upright, same size
convex - virtual, upright, diminished
concave (far away) - real, inverted, magnified
concave (close up) - virtual, upright, magnified
What is refraction
The bending of light as it travels through different mediums of varying densities causing the light to speed up or slow down
What is the refractive index
a measure oh how much a ray of light speeds up or slows down
How do you calculate refractive index
c (speed of light)
——————————— = n (refractive index)
v (speed of light in the medium)
Why do objects seem closer when they are in water
Because water has a different index of refraction - light travels slower in it - when we look at water light from our eyes expects the object to be closer than it actually is but the light hitting the water is slowed down and take longer to reach the object and so the object is actually further away.
What is a critical angle
the critical angle occurs when the angle of refraction goes to 90 degrees when this happens the incident angle is classified as the critical angle and no light can pass the surface it is all reflected
What is accommodation reflex
a response that automatically occurs when you witch focus from an object from one far away to closer you lens will change shapes to allow this
How do we see far away objects
ciliary muscles relxlx, lens is stretched out, suspensory ligament around eyes is tight
